Representing Images

What is a pixel?

What is a pixel?

Smallest unit of an image, that can be displayed and edited, each with its own individual colour stored in a series of binary digits

What is resolution?

the quality of an image, determined by the number of pixels, the higher this is the greater the quality

Effect of resolution on file size

Higher the resolution, the greater the number of pixels, and therefore too the file size

Typical bits per pixel (JPEG)

24 bits

How are bitmap graphics stored?

Stored as a grid of pixels, with each pixel assigned a specific color value and can also be compressed

How are vector based graphics stored

Stored as mathematical instructions to create shapes and lines.

Difference between bitmap and vector based graphics

Bitmap uses pixels and loses quality when resized while vector uses equations and scales without loss of quality.

Formats for bitmap graphics

• .bmp

• .dib

• jpeg

• gif

• tiff

• .png

Fromats for vector based graphics

• .svg

• .cgm

• .odg

• .eps

• .xml